1. Field of the Invention
The present invention relates in general to radio frequency identification tags, and more particularly, to the use of RFID tags to track quantities of loose materials or items.
2. Description of the Related Art
Radio frequency identification (RFID) technology tags are devices that are affixed to various articles so that these articles may be easily tracked during movement from one point to another, or identified through a sales transaction. Any type of object, including assets, animals, and people can be tagged so that they may be identified or tracked automatically via a reader, which is typically connected to a host computer that may contain additional data related to an object's identification number associated with the RFID tag. In addition, RFID tags generally contain program information about an object to which it is attached. Through the use of such information, RFID technology may be used to identify objects automatically and without manual handling operations as is required in most bar code systems.
The operation of typical RFID tagging systems is well known and is not described in detail herein. Many examples describing the operation of such systems can be found, for example, U.S. Pat. No. 5,822,714 assigned to International Business Machines Corporation, the contents of which are incorporated by reference herein.
With the proliferation of RFID tags on products, it is not surprising that their existence on products was leveraged for use outside of the retail establishment from which they were sold. RFID tags were originally designed to assist merchants in tracking inventory within the store and in processing the sale of the merchandise at the check out counter. However, savvy consumers quickly realized that they could also use the existence of the RFID tags in products that they purchased to, for example, keep an electronic inventory of food products, staples, etc. within the kitchen or elsewhere in the home. For example, the same technology used to monitor the existence of products in the store can now be used to monitor the existence of products in the home.
However, a problem exists when an item is of a type that is not consumed all at once and that contains bulk or loose quantities of the product. For example, items such as cereal, flour, sugar and the like will typically be used over a period of days or weeks, and existing RFID tag systems will merely provide the consumer with information regarding the existence or non-existence of the packaging containing the bulk item. Thus, for example, to a consumer, a full, unopened box of cereal will look identical to an almost completely empty box of cereal, i.e., in both cases, the consumer will only know that there is a box of the cereal in the pantry but will not be aware of the quantity of cereal within the box. Accordingly, it would be desirable to have a method and system for monitoring quantities of bulk-type items using RFID tags.